decoder: don't set channels and sample rate in dictionary

This is redundant, the information can already be found in the AVStream
object and is set by avcodec_parameters_to_context. Let FFmpeg take care
of these details.

Change-Id: I199de87a852caeef34047e4f906ccd21dcb696c4
Reviewed-by: Sebastien Blin <sebastien.blin@savoirfairelinux.com>

src/media/audio/audio_rtp_session.cpp

@@ -304,7 +304,7 @@ AudioReceiveThread::setup()
     // Now replace our custom AVIOContext with one that will read packets
     audioDecoder_->setIOContext(demuxContext_.get());
 
-    EXIT_IF_FAIL(not audioDecoder_->setupFromAudioData(format_),
+    EXIT_IF_FAIL(not audioDecoder_->setupFromAudioData(),
                  "decoder IO startup failed");
 
     ringbuffer_ = Manager::instance().getRingBufferPool().getRingBuffer(id_);
@@ -347,7 +347,7 @@ AudioReceiveThread::process()
                 loop_.stop();
                 break;
             }
-            if (not audioDecoder_->setupFromAudioData(format_)) {
+            if (not audioDecoder_->setupFromAudioData()) {
                 RING_ERR("fatal error, a-decoder setup failed");
                 loop_.stop();
                 break;

src/media/media_decoder.cpp

@@ -144,11 +144,8 @@ void MediaDecoder::setInterruptCallback(int (*cb)(void*), void *opaque)
 void MediaDecoder::setIOContext(MediaIOHandle *ioctx)
 { inputCtx_->pb = ioctx->getContext(); }
 
-int MediaDecoder::setupFromAudioData(const AudioFormat format)
+int MediaDecoder::setupFromAudioData()
 {
-    // Use AVDictionary to send extra arguments to setupStream, since video setup doesn't need them
-    av_dict_set_int(&options_, "nb_channels", format.nb_channels, 0);
-    av_dict_set_int(&options_, "sample_rate", format.sample_rate, 0);
     return setupStream(AVMEDIA_TYPE_AUDIO);
 }
 
@@ -197,10 +194,6 @@ MediaDecoder::setupStream(AVMediaType mediaType)
     decoderCtx_->framerate = avStream_->avg_frame_rate;
 
     decoderCtx_->thread_count = std::max(1u, std::min(8u, std::thread::hardware_concurrency()/2));
-    if (mediaType == AVMEDIA_TYPE_AUDIO) {
-        decoderCtx_->channels = std::stoi(av_dict_get(options_, "nb_channels", nullptr, 0)->value);
-        decoderCtx_->sample_rate = std::stoi(av_dict_get(options_, "sample_rate", nullptr, 0)->value);
-    }
 
     if (emulateRate_)
         RING_DBG() << "Using framerate emulation";

src/media/media_decoder.h

@@ -84,7 +84,7 @@ class MediaDecoder {
         Status flush(VideoFrame&);
  #endif // RING_VIDEO
 
-        int setupFromAudioData(const AudioFormat format);
+        int setupFromAudioData();
         Status decode(const AudioFrame&);
         void writeToRingBuffer(const AudioFrame&, RingBuffer&, const AudioFormat);